King County Road Services - Stormwater monitoring and treatment

Overview

Western Washington is no stranger to rain. When rain falls, it flows over roofs, lawns, roads, fields and other surface features before entering the stormwater conveyance system and discharging into receiving water bodies. Stormwater has the potential to pick up various chemicals and pollutants along the way, which may impact water quality in local streams, lakes, rivers, and even Puget Sound.

King County Road Services maintains an extensive network of catch basins, drainage pipes, and ditches throughout unincorporated King County that convey stormwater from the road right-of-way and adjacent properties. Therefore, we have an interest in monitoring and mitigating the effects of stormwater runoff on water quality in our region.

Improving stormwater quality within roadside ditches

Stormwater is conveyed in roadside
ditches throughout much of unincorporated
King County.

In 2008, the Washington State Department of Ecology awarded the King County Road Services Division, Roads Maintenance Section grant funding to try to answer this question: "Is it feasible to improve water quality in roadside ditches?"

We are using the grant funds to conduct two studies. The first is to research existing knowledge on the subject and compile the results for potentially interested parties. The second is to install stormwater Best Management Practices (BMPs) in roadside ditches and evaluate their performance based on monitoring data. Learn more about these efforts:

• Research on treating stormwater in roadside ditches

• Roadside Ditch BMP Project

Have questions?

If you have questions about our stormwater monitoring and treatment efforts, or if you would simply like more information, please contact:

Environmental Unit
King County Roads Maintenance Section
155 Monroe Ave. N.E.
Renton, WA 98056
206-205-7107